package com.antoco.operation.bigscreen.utils;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import javax.crypto.spec.IvParameterSpec;

import org.springframework.util.DigestUtils;

public class EncryptUtils {

  private static String strKey = "Passw0rd", strParam = "Passw0rd";

  /**
   * 对称加密
   * @param source
   * @return
   * @throws Exception
   */
  public static String desEncrypt(String source) throws Exception {
      if (source == null || source.length() == 0){
          return null;
      }
      Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
      DESKeySpec desKeySpec = new DESKeySpec(strKey.getBytes("UTF-8"));
      SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
      SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
      IvParameterSpec iv = new IvParameterSpec(strParam.getBytes("UTF-8"));
      cipher.init(Cipher.ENCRYPT_MODE, secretKey, iv);
      return byte2hex(
              cipher.doFinal(source.getBytes("UTF-8"))).toUpperCase();
  }

  public static String byte2hex(byte[] inStr) {
      String stmp;
      StringBuffer out = new StringBuffer(inStr.length * 2);
      for (int n = 0; n < inStr.length; n++) {
          stmp = Integer.toHexString(inStr[n] & 0xFF);
          if (stmp.length() == 1) {
              // 如果是0至F的单位字符串，则添加0
              out.append("0" + stmp);
          } else {
              out.append(stmp);
          }
      }
      return out.toString();
  }


  public static byte[] hex2byte(byte[] b) {
      if ((b.length % 2) != 0){
          throw new IllegalArgumentException("长度不是偶数");
      }
      byte[] b2 = new byte[b.length / 2];
      for (int n = 0; n < b.length; n += 2) {
          String item = new String(b, n, 2);
          b2[n / 2] = (byte) Integer.parseInt(item, 16);
      }
      return b2;
  }

  /**
   * 对称解密
   * @param source
   * @return
   * @throws Exception
   */
  public static String desDecrypt(String source) throws Exception {
      if (source == null || source.length() == 0){
          return null;
      }
      byte[] src = hex2byte(source.getBytes());
      Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
      DESKeySpec desKeySpec = new DESKeySpec(strKey.getBytes("UTF-8"));
      SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
      SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
      IvParameterSpec iv = new IvParameterSpec(strParam.getBytes("UTF-8"));
      cipher.init(Cipher.DECRYPT_MODE, secretKey, iv);
      byte[] retByte = cipher.doFinal(src);
      return new String(retByte);
  }

  /**
   * 密码加密
   * @param password
   * @return
   */
  public static String encryptPassword(String password){
      return  DigestUtils.md5DigestAsHex(password.getBytes());
  }

  public static void main(String[] args) throws Exception {
      System.out.println(desEncrypt("123456"));
  }
}
